docs: update extWriter (#786)

Author: welkeyever

content/en/docs/hertz/tutorials/framework-exten/response_writer.md

@@ -1,60 +1,73 @@
 ---
 title: "Response Writer Extension"
 linkTitle: "Response Writer Extension"
-date: 2023-03-10
+date: 2023-09-22
 weight: 6
-keywords: ["Response Writer Extension", "Response.HijackWriter"]
+keywords: [ "Response Writer Extension", "Response.HijackWriter" ]
 description: "Response Writer Extension provided by Hertz."
 
 ---
 
-Hertz provides response writer extension, if users need to hijack the writer of the response, they can implement the corresponding interfaces according to their needs.
+According to Hertz's [layered architecture](https://www.cloudwego.io/zh/docs/hertz/overview/), the actual write
+operation of the HTTP response is performed after the application layer user processing logic returns. Under this
+constraint, users cannot flexibly control the behavior of write operations on demand. This limitation is especially
+obvious in scenarios such as controlling chunked encoding write logic
+and [SSE](https://github.com/hertz-contrib/sse#hertz-sse).
 
-## Interface Definition
+To solve this problem, Hertz provides an extension called "Response Writer Hijacking" that can vertically penetrate the
+limitations brought by the layered architecture in an orthogonal way. It allows users to freely customize the logic of
+writing responses in the application layer according to their own needs, improving the framework's ease of use.
+
+## Core Design
+
+### Interface Definition
 
 interface is defined in `pkg/network/writer`.
 
 ```go
 type ExtWriter interface {
-	io.Writer
-	Flush() error
+io.Writer
+Flush() error
 
-	// Finalize will be called by framework before the writer is released.
-	// Implementations must guarantee that Finalize is safe for multiple calls.
-	Finalize() error
+// Finalize will be called by framework before the writer is released.
+// Implementations must guarantee that Finalize is safe for multiple calls.
+Finalize() error
 }
 ```
 
 ### Hijack Your Own Response Writer
 
-Hertz provides `Response.HijackWriter` in `app.RequestContext` to allow users to hijack their own response writer, which provides another way for response writing process.
+Hertz provides `Response.HijackWriter` in `app.RequestContext` to allow users to hijack their own response writer, which
+provides another way for response writing process.
 
 Example:
 
 ```go
-	h.GET("/hijack", func(c context.Context, ctx *app.RequestContext) {
-		// Hijack the writer of response
-		ctx.Response.HijackWriter(yourResponseWriter)
-	})
+    h.GET("/hijack", func (c context.Context, ctx *app.RequestContext) {
+// Hijack the writer of response
+ctx.Response.HijackWriter(**yourResponseWriter**)
+})
 ```
 
 ## Supported Response Writer Extension
 
-Hertz provides `NewChunkedBodyWriter` to create a response writer which allow users to flush chunk immediately during the handler process, it is defined under `pkg/protocol/http1/resp/writer`, and you can implement your own response writer.
+- `ChunkedBodyWriter`: Hertz provides `NewChunkedBodyWriter` to create a response writer which allow users to flush chunk immediately during
+the handler process, it is defined under `pkg/protocol/http1/resp/writer`, and you can implement your own response
+writer.
 
 ### ChunkedBodyWriter
 
 Example:
 
 ```go
-	h.GET("/flush/chunk", func(c context.Context, ctx *app.RequestContext) {
-		// Hijack the writer of response
-		ctx.Response.HijackWriter(resp.NewChunkedBodyWriter(&ctx.Response, ctx.GetWriter()))
-
-		for i := 0; i < 10; i++ {
-			ctx.Write([]byte(fmt.Sprintf("chunk %d: %s", i, strings.Repeat("hi~", i)))) // nolint: errcheck
-			ctx.Flush()                                                                 // nolint: errcheck
-			time.Sleep(200 * time.Millisecond)
-		}
-	})
+    h.GET("/flush/chunk", func (c context.Context, ctx *app.RequestContext) {
+// Hijack the writer of response
+ctx.Response.HijackWriter(resp.NewChunkedBodyWriter(&ctx.Response, ctx.GetWriter()))
+
+for i := 0; i < 10; i++ {
+ctx.Write([]byte(fmt.Sprintf("chunk %d: %s", i, strings.Repeat("hi~", i)))) // nolint: errcheck
+ctx.Flush() // nolint: errcheck
+time.Sleep(200 * time.Millisecond)
+}
+})
 ```

content/zh/docs/hertz/tutorials/framework-exten/response_writer.md

@@ -1,16 +1,20 @@
 ---
 title: "Response 的 Writer 扩展"
 linkTitle: "Response 的 Writer 扩展"
-date: 2023-03-10
+date: 2023-09-22
 weight: 6
 keywords: ["Response 的 Writer 扩展", "Response.HijackWriter"]
 description: "Hertz 提供的 Response 的 Writer 扩展。"
 
 ---
 
-Hertz 提供了 response 的 writer 扩展，用户可以根据自己的需要实现相应的接口去劫持 response 的 writer。
+按照 Hertz 的[分层架构](https://www.cloudwego.io/zh/docs/hertz/overview/)设计，HTTP 响应实际的写操作是在应用层用户处理逻辑返回之后进行的。用户在这个限制下是不能够灵活按需控制写操作的行为的，这个限制在类似控制 chunk 分块编码写逻辑、[SSE](https://github.com/hertz-contrib/sse#hertz-sse) 的场景下尤为明显。
 
-## 接口定义
+为了解决这个问题，Hertz 提供了一个叫做「Response Writer 劫持」扩展，它能够以正交的方式垂直打通分层架构所带来的写响应局限。让用户可以根据自己的需求在应用层自由的定制写响应的逻辑，提升框架易用性。
+
+## 核心设计
+
+### 接口定义
 
 接口定义在 `pkg/network/writer`.
 
@@ -27,28 +31,28 @@ type ExtWriter interface {
 
 ### 劫持 Response 的 Writer
 
-Hertz 在 `app.RequestContext` 中提供了 `Response.HijackWriter` 方法让用户劫持 response 的 writer.
+Hertz 在 `app.RequestContext` 中提供了 `Response.HijackWriter` 方法让用户劫持 Response 的 Writer.
 
 用法示例：
 
 ```go
 	h.GET("/hijack", func(c context.Context, ctx *app.RequestContext) {
-		// Hijack the writer of response
-		ctx.Response.HijackWriter(yourResponseWriter)
+		// Hijack the writer of Response
+		ctx.Response.HijackWriter(**yourResponseWriter**)
 	})
 ```
 
 ## 已支持 Response 的 Writer 扩展
 
-Hertz 在 `pkg/protocol/http1/resp/writer` 下提供了 `NewChunkedBodyWriter` 方法来创建一个 response 的 writer，它允许用户在 handler 中立即刷新分块，用户也可以实现自己的 response 的 writer。
+- `ChunkedBodyWriter`：Hertz 在 `pkg/protocol/http1/resp/writer` 下默认提供了 `NewChunkedBodyWriter` 方法来创建一个 Response 的 Writer，它允许用户在 Handler 中立即刷新分块，用户也可以实现自己的 Response 的 Writer。
 
 ### ChunkedBodyWriter
 
 用法示例：
 
 ```go
 	h.GET("/flush/chunk", func(c context.Context, ctx *app.RequestContext) {
-		// Hijack the writer of response
+		// Hijack the writer of Response
 		ctx.Response.HijackWriter(resp.NewChunkedBodyWriter(&ctx.Response, ctx.GetWriter()))
 
 		for i := 0; i < 10; i++ {